In a semiconductor memory each of the memory cells is accessed by applying a high voltage level to the row line that drives an access transistor for the addressed memory cells. The row line is activated by a decoder circuit which is driven by a multi-bit memory address signal. The row line selected by the address is driven to a high level by the decoder circuit. Heretofore, it has been a frequent practice to permit unselected row lines to float at times when another row line is selected by the decoder. But as memory circuits have become increasingly dense, there can be greater capacitive coupling between adjacent row lines. When a row line is charged or discharged, a voltage will be capacitively coupled into the adjacent floating row lines and the voltage thus coupled can turn on the access transistors from the memory cells connected to the floating row lines. This inadvertent activation of memory cells can destroy the data states stored therein. The most serious coupling occurs between immediately adjacent row lines. Thus, when these memory cells are later accessed, erroneous data will be read out.
In view of this problem, there exists a need for a circuit to drive the row line selected by the memory address to provide access to the memory cells along that row line, but at the same time to hold the nonselected adjacent row lines affirmatively to ground to prevent charging of a nonselected row line by capacitive coupling.